A plug-in hybrid electric vehicle (hereinafter, collectively referred to as ‘MEV’) or an electric vehicle (hereinafter, collectively referred to as ‘EV’) includes a battery that is charged with electric energy required for driving the vehicle from an external alternating current (hereinafter, collectively referred to as ‘AC’) power supply using on-board charger (hereinafter, collectively referred to as an ‘OBC’) mounted within the vehicle.
The OBC includes a high voltage switch, an inductor, a capacitor, an insulating transformer, a relay, a control board, a cooling system, and a separate packaging housing the components and is therefore disadvantageous in a size, a weight, and a price. In addition, the OBC which is not required while a vehicle is being driven but is required while a vehicle is being charged is mounted within a vehicle while being separately configured. As a result, a vehicle weight may be increased, which leads to an adverse effect on driving fuel efficiency of a vehicle.
Further, the related art proposes a structure in which an inverter boosts a household power supply to a targeted voltage and a direct current (hereinafter, collectively referred to as ‘DC’)—direct current (DC) converter forms a simple current pass without performing a switching control to charge the battery. The structure has difficulty of controlling a boost power factor corrector (PFC) when the high voltage battery voltage is less than the household voltage.
When no high voltage DC-DC converter (HDC) is present in the existing motor system configuration, a control is not made when the high voltage battery voltage is less than an input voltage. Accordingly, a separate DC-DC apparatus which may operate as a buck converter is required. Further, the existing inverter integrated charging system structure includes a bidirectional DC-DC converter and performs a boost control using the inverter to boost the input voltage to the battery voltage or greater. Further, the bidirectional converter performs a buck control to buck the input voltage to a targeted battery voltage.
The structure may be applied to a vehicle that includes the bidirectional converter. Further, when there is no bidirectional converter installed within the vehicle, no charging region occurs based on an external input voltage and battery voltage range. In other words, when the battery voltage range is low or AC rectification voltage is greater than battery voltage, no boost charging control region occurs in a low state-of-charge region of the battery.